1. Field of the Invention
This invention relates to a mechanism for supporting a parallel linkage which is generally known as a counterbalanced parallel linkage having counterweights for supporting a weighty equipment or the like in the air,
2. Description of the Prior Art
The applicant of the present invention has previously proposed a Stand Mechanism for a Medical Optical Equipment disclosed in Japanese Patent Laid-Open Publication No. 56409/1989 showing a mechanism of the conventional counterbalanced parallel linkage. That stand mechanism comprises a counterbalanced parallel linkage having a pair of parallel links, each configuration having been transformed linked with each other, and supports a weighty medical optical equipment. This conventional counterbalanced parallel linkage and the supporting mechanism thereof have been capable of performing the following four types of motion:
1. changing the supporting angle of the weight in the lateral direction (transformation of the parallel linkage);
2. motion of the weight in the up and down directions (vertical motion of the parallel linkage);
3. changing the supporting angle of the weight in left and right directions (pivotal motion about the center shaft of the parallel linkage);
4. motion of the weight within a horizontal plane in both back and forth and right and left directions (horizontal motion of the parallel linkage)